Gen-II SAIS Bypass Kit

General SKU: GenII
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43 Review(s)

The GEN-II SAIS Bypass Kits are simply the best solution for your secondary air injection system problems now and in the future.

A complete plug and play kit, which emulates the system by replacing the air injection control driver(s). It does require good pressure sensors (or our PSO add-on) but no other kit add-ons are needed. The only things that need to remain connected or in good condition on the vehicle, as far as the secondary air system is concerned, is the wiring, pressure sensors, and the ECM. No kit addons needed for codes like P0418, P0419, which the GenI kits would need a Pump Proxy Pack for. In fact, the GenII kit doesn't even care if the pumps are still on the vehicle as they will be disconnected from the air injection control driver during install.

Available for ALL of the Toyota/Lexus 2.7L, 4.0L, 4.6L, 4.7L* and 5.7L (including the 5.7L Flex Fuel) engined vehicles.
The Gen-II kits include the module, vehicle specific harness, pair of exhaust block off plates, stainless mounting hardware, Free Priority Mail Shipping and as always, our excellent customer service and Limited Lifetime Warranty! The Gen-II kits don’t stop the system from running like our current V3 and V5 units, they emulate it. The secondary air injection system monitor will even show as complete/ready even with the entire system removed from the vehicle. You can remove the air pump(s), plumbing, air injection control drivers - and by adding Pressure Sensors Options (PSO), you can also remove the air switching valves. (PSO are also needed if you have damaged pressure sensors) Call us for details or for help placing your order!
Gen-II kits are $400 and PSO options are $200 each.

Like all of our bypass kits, these are sold for off-road or competition use only!

*The 07-09 Tundra 4.7L and 08-09 Sequoia are complete plug and play units because their air switching valves are not located under the intake manifold.

*The 05-06 Tundra 4.7L, 05-07 Sequoia 4.7L, 05-09 4Runner 4.7L and all years of the LX470, GX470, Landcruiser 4.7L are not full plug and play units. Because these vehicles have the original system configuration where all system components are located underneath the intake manifold there is no way to make them completely plug and play without removing the intake manifold. Instead, they require 3 wires to be taped directly into the ECM wiring under the dash. These three connections are easy to make with included tap connectors and the instructions include specifics for each vehicle.

Rodney Young on 09/03/2021 06:13pm
Very easy to install on my 2007 4.6L Tundra. Took me just over an hour to install with plates and saved me time and money over fixing the SAIS. Highly recommend and well worth getting the Gen II since it emulates the whole system pretty much.
Kelly McLauchlan on 08/08/2021 07:10pm
I ordered the GenII kit on a tuesday around noon on my lunch break I received It on Trusday at 2:06 from fedEx It took 50 hours to my doorstep wow. I live in northern Alberta Canada. I installed it today took longer than .5 to 1 hour but that`s ok it was me. I do have a bullydog in my 2008 toyota tundra 5.7 I have around 412000 km that`s about 256000 miles on it. the codes came on before install I cleared them then I installed the GenII kit and fired it up and went and drove the shit out it and no codes so far. I drive an 1.5 to and from work so 3 plus hours aday. I am very very impressed with it so for. I can not thank you enough.
Mike S on 07/21/2021 02:38am
Works like a charm! I had code p2438, in limp mode. I bought gen-II kit with the pressure sensor add on for my 2008 tundra 5.7. It only took a little over an hour to install with blocking plates start to finish. Thanks guys, we're back rolling!
Lee on 07/05/2021 02:37am
Shut up and take my money!!! Hardest part was unplugging the one on the passenger side. Literally in a prone position on top of the engine for good 30 min just to get one plug off. Put a thick blanket over the engine bay so I can lay on top of it. Finally got it off by using a telescoping mirror and a pick. $400 seems a lot of money but trust me, worth every penny.
Jared on 07/01/2021 08:37am
Just bought a sequoia with 5.7 from a dealership. 24hrs after purchase the truck went into limp mode and threw a p2440 code. This seemed suspicious after purchasing the truck with no warranty from the dealership. they did not care or did nothing to help me. The repair bill was $3500 from a independent shop. Thank God that this bypass kit was available.
Kevin Wilbourn on 06/10/2021 06:45pm
At 10.5 years and 157k miles, I got the dreaded CEL and Traction lights with limp mode. Code pulled was 2442 on my 2011 Tundra 4.6L. (Bank 2 SAIS Valve stuck open). If it's not clear, limp mode = bad shifting, horrible throttle response, rough idle, and about 6 MPG. I drove mine a minimal amount in this terrible state, and ordered the bypass Gen 2 kit right away. 5 stars isn't enough to cover this product. The directions were fantastic, the product was packaged very well. I managed the install over my lunch break, and I'm a computer geek, not a mechanic. From what I've observed online, the 4.6 may be the easiest motor to install this kit on. You need a phillips screwdriver and a 10mm socket, that's really it. After the install, my truck runs great! Comfortable idle again, solid power, and the fuel economy is better than it has been for some time. So glad I did the bypass kit rather than shelling out a lot more money to replace parts that are going to themselves wear out in a few more years.
Jeremy R. on 05/07/2021 07:53am
You've got to read this review. I have a 2018 Tundra crew cab. One of the things I have always done to my trucks is install a remote start. Well, one day I noticed the remote start was not allowing my truck to run after starting. It would start, self analyze and then self stall. It would go through this 3 times before shutting down. I thought I may have had a bad remote start kit and then I started to do research. The first time I heard the "vacuum cleaner" noise was when I was driving through Texas on a sub 30 degree day. I lost a lot of power and thought I got bad gas or it was the cold weather. Maybe the truck was made for hot weather?? Any way, I was able to make it home and in that time I NEVER got any trouble codes or dash lights. After reading about all of the people having problems with the SAIS, I decided to see if Toyota would fix it. They in fact had an extended warranty for many years in order to fix or replace the SAIS but I did not want them to pull the engine to fix these air injection motors because once an engine is pulled, it will never be the same.
I think the fact the government INSISTS that vehicles have SAIS is sinister. Of course they are not our friends and I am not surprised that the government makes all vehicles be "50 state compliant" when it is really California that is making all these crazy emissions rules! OK.enough about politics. So, I read all of the reviews and I saw how expensive the GEN II bypass kit was, but several of y'all just said to bit the bullet and go for it. I am very glad I did! Even though my truck was not throwing codes simply suggests that the truck was using the SAIS system as intended. But, it was obviously still causing problems.
INSTALL: I am a handy kinda guy but it still took me almost 3 hours. First hint is to work on your truck when it is cooled off! Finding the connections was easy, but getting the passenger side plug off and then plugging in the new one took an hour (damn big hands!) The second part was installing the exhaust intake plates. They are easy once you get the hang of it. The one thing I want to point out is on the video and in the directions, it shows that you need to remove the rubber shroud before you can access the ports. That is true for the passenger side, but on the DRIVERS side, exhaust port is closer to the firewall and there is an open area (no rubber shroud) FYI. I used a stick about 3/4" in diameter to push up on the white metal tube behind the port. Get a stick about 22" long, weave it through the engine and various hoses from under the engine. Once it is in place, I used a jack to gently lift these tubes and the plates easily slipped in. RESULTS: The first time I started my truck, it was much smoother. It has a nice throaty sound like it was designed, but it settled into a gentle purr rather than ramping up the RPM's like it had been doing for the last year or so. I took it out on a test drive and I was able to scratch the pavement.I am telling you, the truck has not had this much power since I left the dealer. The next morning I used my remote start and the truck started up with no issues. Finally, I wanted to say that when I made a 10 hour trip down to Florida, I got 18.1 MPG running at 75 MPH and a smooth and consistent 2,000 RPM. I have NEVER gotten that good of gas mileage. The best I ever got was 17.6 MPG so that puts this as a 3% fuel increase. That is a 1/2 a mile per gallon increase.not much right? But with a 38 gallon tank, I will get an extra 19 miles which is about a gallon of fuel!! This device may not have been designed to increase fuel economy or make the truck run better, but I assure you, it did. Simply amazing and a pleasure doing business with you! Also, I got the device in the mail in two days. Fast, free shipping.
Keith on 03/29/2021 11:47am
2010 Tundra 4.6L throwing SAIS trouble code. I'm handy but not a mechanic. The Gen II was easy-peasy to install and works as advertised. Well designed and manufactured, good installation documentation, and from what I can tell high quality materials. I discovered that when the ECM is cleared due to disconnecting the battery (which is part of the installation process)the engine dies after the first re-start and throws a P1604/1605 which, according to my research, will clear after the ECM relearns lost parameters after 50-100 miles of driving. Just be aware of this anomaly. *Edit - Hey Keith, thank you for the review. It is perfectly normal for the engine to stall on the first start after resetting the ECM (this info is in the last steps of the instructions). However, we have never seen the initial stall out cause a stall or start-ability code since the ECM knows it was just reset. It could have been a special case but if they don't clear by themselves just reset the codes again or use an OBDII tool to clear them at this point.
john mullen on 03/29/2021 11:32am
ronnie in ky on 03/23/2021 07:50pm
normally dont write reviews but this product has cured my ailing tundra. the gentleman i spoke to was knowledgable and helpful. the kit, literature and instructions was dead on and had it installed on a cold winter day in about 30 - 40 minutes. its been on by tundra for over 3 months with perfect function. highly recommend to anyone with this issue. saved $1800 in repairs and got rid of a reoccuring problem.
Colton Estes on 03/09/2021 06:45am
Great product! Did the install in one afternoon no problem. Hardest part was working around this gut of mine!
Susan on 03/05/2021 08:41pm
Purchased to Canada for a 2008 Toyota Sequioa. Worth Every Penny, Easy to install, beat the $1800/quoted fee to replace all parts. Duties/Tax was only $35 Cdn
BEM on 02/13/2021 12:19am
The Gen II SAIS has worked well for long enough that I feel comfortable saying that it was well worth the price. I have an 07 Tundra 4.0L and have had no CELs and no limp mode issues since installation.
Michael Bean on 02/01/2021 08:22pm
I should have purchased the gen II kit from the start. took me 45 minutes to install and erase weeks of worry and pathetic response/power out of my 2010 Tundra. Drives like it should again! Dont think, just buy one if you are also facing the same sais issues.
Susan on 12/31/2020 05:01am
Purchased the Gen 2 for our 2008 Sequoia. Easy to install, runs like a charm. We are in Canada, and the fees/duties were under $40CDN. Sure beat the $1800 repair quote anyday !! Thank you !!
MARK FRANKLIN on 11/29/2020 05:12pm
Wanted to wait before i posted a review.I have had this on for over a year now.No issues at all.Truck is running great.I would highly recommend this to anyone wanting a permanent fix to the air pump issue on the Tundra. Hewitt tech was very professional at helping me with the gen 2 bypass kit. Definitely buy this if you want to fix the issue.
Jose vejar on 11/23/2020 07:40pm
I ordered the Gen-II SAIS Bypass Kit For my Toyota Tacoma 2.7 2013. Very easy to install, it Came with the instructions. I have it in my truck for two months and it is working like a champ. Quality all over. It is made in the great USA. I can STRONGLY recommend this kit. I am very happy with the service and product. Big thanks to that came with this ingenious solution.
Oscar on 11/17/2020 03:11pm
Highly recommended. quality products excellent customer service.
Chad T. on 11/11/2020 06:20pm
2011 Tundra 4.6 with a P2440 code. Shop wanted $2800 to fix. A buddy told me about Hewitt-Tech, and I thought surely this is a screw job for $400. It doesn't take a mathematician to look at the two costs and decide, so I gambled. It's a sure win! The truck cranked right up, no codes, and seems to drive beautifully.
Danny on 10/23/2020 10:12am
Gen 11 SAIS by-pass kit works awesome . No more codes and best of all no more limp mode . Shipping was fast to PEI Canada . Thank you
Dylan Jochim on 08/17/2020 12:52pm
My 08 Tundra went limp & threw code p2442. Price quote from a local mechanic was $2200. I purchased the Gen 2 Bypass kit and it solved my issue completely. Worth every penny! Thank you Hewitt Tech so much!
Ted Davies on 07/16/2020 02:20pm
I just finished installing. I am very happy so far but just a few comments. Removing the wiring harness on the passenger side is a real PITA. It may be easier on newer models but on my 2008 Tundra it took over an hour for the connector removal. I was almost at the point of removing the intake manifold. Also there are now 2 plugs in the kit. I called and they recommend removing both bank 1 and 2 modules and putting plugs in the unused wire connectors. This is NOT what they recommend in their Youtube video. In closing although I have skin scraped off both arms to the elbow the module is working and saved me a pile of money **HT Review Response** Hey Ted, thanks for the review. It sounds like you may have watched a V36H Gen-I unit installation video which are only for the 2005-2007 model years. We do have a video of the Gen-II 5.7L installation which is indeed completely different and points out some tricks to make it easier to get to the 5.7L's air switching valves that are located behind the intake manifold. Unfortunately that is where they are on the 5.7L while they are so easy to get to for all the other engines. For the time being the I am glad we were able to get you installed and all fixed up.
Rob M on 06/29/2020 02:40pm
I%u2019m so glad I found this kit. My 08 tundras secondary air injection pump system began to fail and the dash lit up like a Christmas tree. Toyota wanted $2300 to fix it and since my truck is an 08 it didn%u2019t qualify for the extended warranty. I have absolutely no experience working on cars. I was hesistant to do this myself but somehow managed to install this in just under 3 hours. No more lights no more limp mode. It%u2019s been 4 days so far and all is good. Thanks HT!
Bob on 06/22/2020 04:17pm
This bypass kit worked very well and was an easy install. The toughest part was the block off plates on the ais valves, which I was able to do with a 10mm combination wrench from topside on the truck in stead of taking off the tires and wheels to access thru the fenders. I just tied a length of paracord onto the open end side of the wrench in case I lost my grip on it so I would not lose it into the abyss of lower engine compartment. I also sprated the nuts on the valves with pbblaster for 2 dats prior and once I broke them loose I could turn them by hand.
Lo Lee on 06/17/2020 05:44pm
I had this problem 1 since I got my truck in 2016. Found out the issue what it was & was unable to afford the air injection pump & the air check valve from the dealer. I got better price from rockauto But was afraid to buy it to due to the warranty they have. So did a research about it,, then decided to clean the pump & the valves. After that it lasted about a month. Same thing going on, throwing codes like crazy. On limp mode again. Waited 2 years doing more research on it. Came across Hewitt tech the bypass kit. Was hesitating as well due to kit, is it going to work? Talk to The agent there. Becky did a good job telling me what's going on if I were to replace the component. It'll last about a year or 2. Ask around whoever has the same issue. A lot people don't replace it, just bypass it. Did research on the review in Hewitt tech. Everyone seems to have all good review so decided to lose 400 bucks with lifetime warranty. It's way better than warranty that lasted only a year or 2. Did the order, it item was here after the weekend, which shipping is free to, installed. It's been 3 days, no more codes or check engine light, no more limp mode, truck is strong as it was when first got it. Happy for the purchase. You shouldn't be hesitating in this order. It will help your truck stay the same & strong as before when this haven't happen. I have 08 4.7L engine.
Ed Kennedy on 06/13/2020 10:25am
Product worked as stated. Took me about an hour to install. Had a P418 code. Dealer wanted $3100 to fix. Saved $2700 by installing bypass kit. Great product!!!!
Ziggy on 05/28/2020 09:20am
I have had this installed for one week. Works great. Staff was impeccable. Life is good
Randy Craft on 05/20/2020 09:35pm
To start. If your're getting air injection code issues on your tundra buy the Gen ll bypass! Threw 2 air injection driver codes (1613 and 1614) last year. Changed the drivers. $200 mistake. And was still in limp mode but was able to run the truck normal if I warmed the truck up, turned it off and started back up. Codes never cleared but it was a "fix" until I threw a 1224 code (stuck AIV bank 1) last week. What an air injection mess Toyota designed here. Contacted Hewitt Tech and Becky in support and she convinced me to buy the Gen ll bypass. Easy directions and install. Just had to move a few minor things around to get at the ASV's. All 3 codes are gone after startup. Thanks Hewitt Tech
Jason on 05/08/2020 07:50pm
All I can say is Hewitt is awesome. My truck threw code 2442 on Monday of this week, crippling it to limp mode. I had code 2441 prior and knew the issue was there. My truck was bought used with and extended warranty, cool until I find out the deductible and that they only cover X amount of labor dollars.headache! This is a work truck, down time is money lost. I was planning on doing the bypass at some point anyway but at this point I could spend less on the Gen 2 kit then it would cost to get it repaired under warranty. I called Hewitt to make sure the kit would fix my issue, was looking at the old kit versus the Gen 2. after a 5 minute convo and advice from the tech advisor that the Gen 2 would be a one and done unless I had a bad pressure sensor( which he advised given the run down of the truck symptoms that I did not), he suggested going with the Gen 2. I ordered the Gen 2 kit at 3 pm, that day and paid for next day shipping, 1115 am the next day package on my doorstep. Started install around 2, was on the road by 430 all fixed and back to work! All I can say is the service and speed of Hewitt Tech is awesome and refreshing, thanks for the help and getting me back on the road fast! Install went just as the You Tube vidoe showed, but was helpful having my teenage daughter to slide that driver block off plate in. Thanks again!
Dana McFarlane on 05/08/2020 04:10pm
Had the same issue most on here had with my 08 Tundra 5.7 Ordered the Gen II kit and attempted to put the block offs in myself, but was not able to, simply do to working on a jack stand and in the drive. tough angle to get to. so called my Mechanic friend and we took to his shop, he helped me install the block offs in about 20 mins and the rest of the kit in about 15. Very easy process if you have the right tools and access. I am very happy with the kit so far and it did get rid of the errors. I would recommend this to anyone having this issue! Thank you Hewitt!
Cam on 04/20/2020 08:11pm
Super easy to install. It only took a little over an hour with the included, simple to follow instructions. Works like it is supposed to.
Bill on 04/07/2020 07:34pm
The Gen II by-pass worked better than I expected. Like most, I started my research online and after reading and looking it Hewitt-Tech, they delivered as promised. Spoke with Becky first through their online contacts and she answered all my questions. I called after hours and to my surprise, Paul answered the phone shortly after their closing time and set time aside to ensure I had everything I needed to correct my 2011 Tundra 5.7L Crewmax. Awesome job Paul, your team was great to deal with and provided me with the confidence to trust your product. Furthermore, the by-pass corrected my P2440 code and cleared my issues. The exhaust block off plates were tricky to install and utilizing the "dowel rod" method slightly bent one of my bolts but utilizing a deep well socket and universal with an extension seemed to work better on those stubborn angles. Either way, great job and thank you for your time and effort. Much appreciation.
Frank Vasquez on 03/28/2020 03:57pm
I don't normally write reviews unless the product or the service is really awesome or really bad. This product is 100% legit and will save you thousands. My dash board was lit up like a Christmas tree and after installing this I have no lights on and truck runs great! Not only is the product great, but so is their service. I destroyed the connector on the back of the motor on the passenger side. I couldn't get it disconnected with my fat fingers, so I tried using needle nose pliers and destroyed the connector and some wires. I called them to see if they could help me with obtaining a new connector. I forget who I spoke to, but it was a female and she was so helpful. She knew exactly what I was talking about, but asked for a few pics just to be sure. I sent the pics and we made the transaction happen. She even sent a hand written wiring diagram, so I could connect the wires correctly. I can't say enough good things about their product and service. Thank you!
J Thompson on 03/23/2020 09:14pm
I give my mechanical abilities a rating of 3 or 4, I can manage simple repairs but usually send it into the shop for more complicated repairs. However, when the repair shop said it was going to cost $2500 to $3000 to replace the air injection pump I decided to give this option a chance. I am happy to announce I was able to get the kit installed and have driven the truck a couple of hundred miles without any issues. By far the hardest part of the install was reaching behind the engine to disconnect the original wires from the air pump. I almost gave up thinking I was tearing the wires. I emailed the support team for help and they responded quickly and gave some additional helpful hints which was all I needed to complete the job. I would highly recommend this product.
Thomas Colby on 03/02/2020 08:55am
I just wanted to let you know how pleased I am with the product you all have available for the common problem occurring with Toyota SAIS. It's not often that you call to obtain information on a product and you find someone so knowledgeable in tech support regarding the issue at hand. Install was smooth and straightforward with detailed instructions and my CEL/limp mode issue is a thing of the past now. When given the chance, I will surely let others know of your solution that's a fraction of the cost of a pump/valve replacement. Thanks again! -Colby T
Brad on 02/18/2020 10:25pm
...The kit fixed my truck immediately and no codes ever popped back up. My truck also seems to idle better now. Would definitely recommend.
Vitus on 02/16/2020 04:21pm
Thought it was too good to be true. But it ends up to be true. It works!
Gary on 02/10/2020 11:45am
Yes, I was skeptical up until i said a prayer, then turned the key. Now I'm elated!!! Researched til I was sick and took a chance on the company and Gen II product. Professional and honest folks and an ingenious solution to a major problem. I just installed yesterday and got in no hurry, about an hours work on my 2008 tundra with 4.7l. Blocking plates were the most aggravating, but done with a pivothead 1/4 " ratchet. Instructions are a work in progress but enough info to digest for a successful install. Would recommend vacant plug covers when available, and specific instructions for individual models. SOLVED MY P2444. Thankyou guys!!!
Mark Kolvites on 10/19/2019 08:43pm
Excellent product - worked great for my %u201813 Tundra.
I also added the Pressure Sensor Option - that was needed in my case and worked great. Well made product - great customer service to help work through any questions. It%u2019s not cheap, but has been worth every penny since repairing my truck almost 2 months ago.
Steve Medford on 09/16/2019 12:16am
Like some of the others, I bought my Gen II prior to installation instructions, however, Becky walked me through every step and question I had. I live in TX, did the install and made a 2wk long hunting trip in mountains of Colorado. The Gen II worked flawlessly at all altitudes and in all early morning temperatures, CODE FREE! And honestly, my 2012, 5.7L Tundra, seems to be a little peppier, maybe a little quicker, haven't check it yet, but maybe a little better fuel mileage. VERY pleased customer here! Definitely 5 stars! Thank you Becky and the gang!
Chad on 09/14/2019 03:00pm
I was looking at facing thousands of dollars in repair costs and was not about to do that. I did some research and found this product online and after looking at multiple videos and reviews I decided to check it out. I'm very glad I did it's a great product and save me a lot of time and money. I highly recommend this bypass as opposed to paying through the nose at the dealership. Thanks again guys for all the help.
Jerry Delong on 09/12/2019 04:26pm
I installed one of the gen 2 kits before there were even instructions . I installed the plates as well which is a bit tricky . The system did work and is still working fine. I recommend some dummy plug covers for open connectors but over all it's a good solution for a big problem .
Clark on 09/08/2019 02:16pm
The Gen II SAIS by-pass has been installed for about a month now. The 4runner is running without throwing a code or going into that darned limp mode. I luv it!!!
Installation took less than 30 minutes, and if you ever had to install a 2nd one, likely install in under 5 minutes.
My 4runner is a "project car" (and daily driver); I bought it as a salvage car, having gone (entirely?) underwater during TX Hurricane Harvey. Over 10,000 miles on the car since placed back in service early last year. The SAIS, one of a number of minor electrical issues, now being sorted out.

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